The Michelson-Morley Experiment: Ending the Ether Theory

In the 19th century, scientists believed light traveled through a mysterious medium called the “luminiferous ether.”
Albert Michelson and Edward Morley set out in 1887 to detect Earth’s motion through this ether.
They used an interferometer, a device that measures tiny differences in light’s travel time.
If ether existed, light should have moved faster in some directions than others.
The experiment found no difference at all—light’s speed was constant in every direction.
This “null result” shocked the scientific community and challenged long-held beliefs.
It became one of the most famous negative results in the history of science.
The failure to detect ether paved the way for Einstein’s special relativity in 1905.
Einstein explained the result by showing that space and time adjust so light’s speed is always the same.
The experiment is now celebrated as a turning point that transformed modern physics.